Siftproof carton



Patented Aug. 20, 1946 21,406,061 SIFTPROOF CARTON Thomas F. Cass, Jr., Wayne, lll., assignor to Container Corporation of America, Chicago, Ill., a. corporation of ,Delaware Application April 28, 1944, Serial No. 533,128

4 Claims.

`l yThe invention relates to sift-proof cartons, and more particularly to cartons especially adapted for packaging finely divided material, such as salt, sugar, soap flakes and washing powder. The principal object of the invention is to provide a carton which may be tightly sealed l so as to prevent loss or sifting of material from the carton. Another object of the invention is to provide a sift-proof, lined carton which may be moisture-proof and grease-proof. n

In accordance with the preferred embodiments of the invention, these are accomplished by providing a paperboard blank from which the carton is to be formed with a lining sheet preferably secured thereto by means of an adhesive, such'as amorphous wax or a similar composition. The` blank is then die-cut to form end aps, but instead of cutting the entire flap through the paperboard and liner a portion of the liner is left uncut so that when the inner end aps are folded downwardly the uncut portions of the liner will draw away from the adjacent flaps and form a bellows corner, and when the seal is completed by folding down the outer flaps a completely sift-proof carton is provided.

The invention will be more readilyr understood by reference to the accompanying drawing and the following detailed description, in which are set forth an illustrative embodiment of the inventive thought.

In the drawing:

Fig. 1 is a plan view of a lined blank from which the carton may be formed;

Fig. 2 is a View of the carton embodying the invention, with all but one of the end flaps turned down, the turned down outer end flap being partially broken away to show the bellows corner by means of which the sealing is obtained;

Fig. 3 is a detailed fragmentary view of one of the corners of the box before the end flaps have been turned down, this View showing the extension sealing flaps of both .the carton and the liner;

Fig. 4 is a sectional view on the line 4-4 of Fig. 1;

Fig. 5 is a sectional view on the line 5-5 of Fig. 2, but with the 1ast of the sealing flaps closed; and

Fig. 6 is a detail perspective view on an en- I formed of ordinary paperboard, and the other layer comprising a suitable liner B which may either be a paper sheet secured. to the paperboard portion by means of an adhesive such as amorphous wax or similar composition, or may be a moisture and vapor-proof substance such as glassine, parchment, cellophane, Pliofilm or the like.

Referring to Fig. 1, the carton blank as shown comprises a body portion including a pair of wide panels I0, I0 and a pair of narrow panels II I I, although if desired all the panels could be of the same width. Extending beyond one of the narrow panels I I is a lined sealing flap I2, While extending from the opposite panel Ill is an extension I3 of the liner B only, the stock portion A of the carton terminating at the Vertical line I5 and its extensions 22, 22. The panels I0, II and I2 are separated from each other by any suitable means, as for example vertical score lines I4, I4, while horizontal score lines I6, I6 may be provided for separating the main panels III and II from sealing panels I'I and I8, the reference numerals I'I designating the relatively wide extension flaps, and the reference numerals I8 designating the narrow extension flaps projecting beyond the panels II, II. The liner extension I3 may also be provided with extensions I9, I9 separated therefrom, if desired, by suitable score lines'.

To form the sealing or extension aps I'I and I8 the blank is die-cut in such a manner that slots 20 are formed separating the aps, which slots extend entirely through the paperboard portion Aof the blank to the horizontal lines I 6, and also extend through the liner down to points a short distance from lthe fold line, leaving unsevered portions 2| which, when the extension flaps are folded down, are adapted to form corner seals which eifectively prevent sifting of the material. Similarly the liner iiap portions I9 are separated from the flaps I'I by means of cuts 22 which extend down to uncut portions 23 corresponding with the uncut portions 2l, 2| at the ends of the die-cuts 20.

In setting up the box the panels are folded to tubular form along the lines I4, III and are secured in place by means of the external ap I2 and the internal liner extension I3, these being preferably secured in place by means of Suitable adhesive. These iiaps in their securing position are indicated in Fig. 3. It will be noted that as shown the flap I2 terminates short of the sealing flaps I'I and I8, whereas the portions I9, I9 of the liner extension I3 extend to the ively secured to its entire inner surface,'said outer limits of the sealing flaps II and I8. blank being cut and scored to provide a plurality To close the carton the narrow flaps I8, I8 are of side wall panels and closure flaps integrally rst folded downwardly into horizontal position, joined to said panels along a score line, said as illustrated in Fig. 2. As these aps are folded 5 closure aps being deiined from adjacent flaps into sealing position the uncut portions 2|, 2| by cuts in said sheet of paperboard extending of theliner will tear away. from the adjacent outwardly from said score line and cuts in said flaps I'I,v I'I andform-abellows corner 25. When .sheet of lining material coinciding with said the seal of the box is completed on folding down `inst-mentioned cuts but extending outwardly the outer iiaps II, I'I the bellows corner will-be 10 only from points substantially outwardly spaced folded over, as indicated in Fig. 5, and will be :from said score line.

retained between the various layers of;1the...end 3.A folding carton formed from a sheet of sealing iiaps, thus effectively` preventing sifting paperboard having ,a sheet of lining material of the contents. securedy to its entire inner surface by means of The invention has beendescribed in detail' for"l5.anamorphous wax or similar adhesive comthe purpose of illustration. It will be obvious prising four rectangular side wall panels having that numerous modifications' and variations'may integral rectangular closure flaps joined thereto be resorted to without departing from` the spirit alonga-score line, a lateral extension of said paof the invention Thus the composition ofthe perboard on one of said side wall panels adapted liner may be varied as desired, and also the flap 20 to be secured to another of said side wall panels "extensions 'I2 and I3 may be varied or omitted, to form a tubular carton body, a lateral extension *provided'other'suitable corner-sealing means is ofsaid lining material on one of said side wall substituted. 'The' size of the bellows corners 25, panels, and an end extension on said last-menl25"wil1 be dependent lon the length of the cuts tioned lateral extension, the paperboard portions 42l,` 2l, but should preferably be comparatively 25 of Vsaid closure iiaps being dened from each HIsnialler-andonly s'uicient to eiectively close the other by cuts therein extending outwardly from `corners of the cartons. 'said score line and the lining material portions I claim; of said closure flaps and said end extension be- 1;'A folding carton-formedfrom a sheet of ing defined from each other by cuts therein expaperboard having a sheet'of lining material ad- T30 tending outwardly only from points substantially "hesively secured to its entire inner Asurface inoutwardly spaced from said score line.

icluding aplurality'ofadjacent side wall panels '4. vA folding carton formed'from a sheet of and a plurality of closure flaps integrally joined 'paperboard having a1 sheet of lining material to -said Ypanels along a' score line, said closure secured to its entire inner surface by means of iiaps being deiined from 'adjacent flaps by cutsf-35 an amorphous wax or similar adhesive including extending completely through said sheet of paa` plurality of adjacent side vpanels and a pluperboard substantially to said score line and exrality of closure naps integrally joined to said tendingL through said sheet of lining material ypanels along a scoreiline, said closure flaps being `only to pointsslightly but substantially removed 'defined from adjacent iiaps by cuts extending '"frorn`said score'line. ('40 completelythrough said paperboard sheet out- 2.`AV folding carton blank having elements wardly from said score line and extending outadapted-'to provideY a sift-proof closure at least wardly through said sheet ofv lining material only at one end thereof comprising a sheet of Vpaper- V'from points spaced outwardly of said scoreline. *"boardhaving-a'sheetfof liningrrmate'rialadhes- VTHOMAS F. CASS, JR. 

